This invention generally relates to the evaluation and regulation of male fertility.
On one hand, it is estimated that one in every five couples in the United States has fertility problems, of which approximately 40% are due to male deficiency. The male deficiency most commonly responsible for infertility is a deficiency in sperm production both in quantity and in quality. A variety of methods have been used for treating male infertility, relying on diverse mechanisms including the induction of intracellular glutathione synthesis in the male reproductive system (U.S. Pat. No. 5,389,657), administration of human growth hormone (U.S. Pat. No. 5,250,514), administration of testosterone analogs (U.S. Pat. No. 5,596,004), and use of medicinal tea (U.S. Pat. No. 5,736,144). Additional methods and compositions are described in, e.g., U.S. Pat. Nos. 6,197,940, 6,235,783, and 6,555,140, for treating male infertility. The high prevalence of male infertility demands new and effective diagnostic and therapeutic methods.
On the other hand, prevention of unwanted pregnancy in human and other mammals is an important task in both developed and developing nations. A large number of methods and products have been developed and in wide use for this purpose. For instance, well over 100 million women each year rely on oral contraceptives to prevent unintended pregnancy. With few exceptions, these methods and products focus on suppressing female fertility. Although some new methods and compositions for controlling male fertility have been described in, e.g., U.S. Pat. Nos. 4,225,590, 5,739,124, and 6,521,641, there remains a need for developing new and effective male contraceptives.
This invention addresses these and other related needs.